Add keep_memtag_mode extra to FACTORY_RESET intent

This allows to keep the MTE state when resetting the device. This is
used in TestHarness to avoid an extra reboot to re-enable MTE after
reboot.

Test: atest FactoryResetterTest
Test: atest MasterClearReceiverTest
Test: adb shell cmd testharness enable --keep-memtag
Test: adb shell cmd testharness enable
Bug: 300694575
Change-Id: I8f57c9c3ef98678e9a1b5e0c5b30794f9788758f